Frequently, utilities will lay cable in or adjacent to a railway bed. There are several advantages in doing so. First, the right of way provided by the railway can avoid time consuming efforts to obtain right of ways from property owners located along the proposed cable route. Second, such cables need not have supporting structures such as posts and the like since they are buried underground. Thirdly, damage to the cables is minimized since they are not exposed to the weather elements and are less likely to be damaged by digging, maintenance operations and the like.
Laying cables in or adjacent to a railway bed is known. Heretofore, such cable laying has been accomplished by two principal techniques. The first technique is to use a railway car such as a flatbed which is connected to a locomotive, the locomotive providing the source of power for movement of the flatbed. Two cable ploughs are mounted on the flatbed, one to lay cable on one side of the flatbed and one to lay cable on the opposite side of the flatbed, as the operator may desire. A reel holding the cable is also mounted on the flatbed and feeds the cable to a respective plough where the cable is laid under or adjacent to the railway bed.
This technique, however, suffers inherent disadvantages. First, the capital cost of the equipment utilized is unnecessarily high. Second, if a train is required to use the same tracks as the cable laying equipment during the cable laying operation, the locomotive and flatcar must find a siding where the train may pass. Such a siding may be located a good distance from the working site of the cable laying with the result that there is a non-productive transportation downtime involving all of the expensive equipment. In addition, the train itself may be delayed. Third, since the cable used is mounted on the flatbed car adjacent the cable ploughs, when the equipment reaches a position such as a highway or bridge where the cable must be manually laid, the cable laying equipment will necessarily again be non-productive while the cable is removed from the cable reel, manually positioned, and then rewound. Since the cable may be well over two miles in length, the downtime of the equipment can be lengthy and costly.
A second technique used to install cable is by mounting a cable plough in the centre of the lagging end of a crawler and providing cable to the plough from a cable reel mounted on the crawler. The crawler straddles one rail of the track and the cable plough will be operable from the centrally located position on the crawler and extend outwardly on one side of the rail to lay the cable.
This technique again offers disadvantages. First, the crawler track can cause considerable damage to the ties on which the rails are mounted. Second, there is again considerable and non-productive downtime of the equipment when it is necessary to remove and rewind the cable from the reel. Thirdly, when it is necessary to remove the crawler from its working position straddling the track due to train movement or the like, it is difficult to do so without providing a surface for the crawler track on which the crawler may turn in order to move clear of the rails. This is inefficient and unnecessarily costly.